The present invention comprises an industrial scale fluid flow control valve of sleeve diaphragm design.
There are some inherent disadvantages in the physical construction and operation of present art tube diaphragm, or sleeve, valves. For instance, cavitation is not unusual at normal flow rates when the valve is connected to an open discharge. Present art valves also incur more or significant head loss. And upon occasion the conventional tube diaphragm, or sleeve, is damaged when the valve flanges are tightened beyond torque tolerances.
Advantages of the present design over existing valves are that the instant design does not require a cage to be associated with the core for diaphragm support. Rather, a generally concave deformable elastomer tube, or sleeve, of cylindrical shape, flexes and stretches between a "loaded", or deformed, open position and an "unloaded", or at rest, closed position. The sleeve preferably includes longitudinal and circumferential integral ribs, and the core preferably offers a mating concave surface to the sleeve. The concave shape of the sleeve is preferably an inverted sphere. This design incurs significantly lower head loss and provides a larger fluid passage with less turbulence within the valve than current designs on the market. Also cavitation does not occur at normal flow rates when the valve of the present design is connected to an open discharge.
U.S. Pat. Nos. 5,090,660 and 4,023,772 to Ratelband, U.S. Pat. No. 4,796,804 to Weiss, U.S. Pat. No. 5,035,259 to Allen, and U.S. Pat. Nos. 4,824,072 and 4,451,023 to Zakai disclose diaphragm valves that include sleeve-shaped elastic diaphragms which, although similar in some respects, are opposite in other regards to the present invention. For instance, Ratelband, Weiss and Zakai all appear to teach, to the contrary of the present invention, valves that are closed in their "loaded" or deformed condition and open in the "unloaded" or at rest condition. The present valve, by contrast, is designed to be closed in its "unloaded" at rest condition. Also, none of the art teaches longitudinal integral ribs on the sleeve, a core with a mating concave sealing surface, or a concave sleeve shape that comprises an inverted sphere.